Rubus preptanthus Focke

Shrubs scandent. Branchlets brownish to grayish brown, gray tomentose when young, gradually glabrescent, with sparse, curved minute prickles or nearly unarmed. Leaves simple; petiole (0.3–)1–2 cm, tomentose, usually unarmed; stipules caducous, lanceolate or linear-lanceolate, 0.8–1.4 cm × 2.5–5 mm, membranous, appressed villous; blade oblong-ovate or broadly ovate-lanceolate to narrowly lanceolate, 6–12 × (1–)3–5.5 cm, lateral veins 6–9 pairs, prominent abaxially, papery, abaxially densely gray to yellowish gray appressed tomentose, adaxially glabrous, base rounded to subtruncate, margin unevenly incised coarsely sharply serrate or sparsely so, rarely doubly serrate, apex acuminate. Inflorescences terminal, racemes, 4–8 cm, several to more than 10-flowered; rachis and pedicels densely gray to yellowish gray tomentose-villous; bracts caducous, lanceolate to linear-lanceolate, 0.8–1.2 cm × 2–4 mm, membranous, villous. Pedicel 7–10 mm. Calyx abaxially densely gray to yellowish gray tomentose-villous; tube pelviform; sepals triangular-ovate to lanceolate, 8–10 × 3–5 mm, margin entire, apex acuminate. Petals white, obovate, 5–7 × 4–6 mm, both surfaces puberulous. Stamens many, shorter than sepals, glabrous or hairy when young, or only anthers slightly villous; filaments inflated at base. Pistils slightly longer than or nearly as long as stamens; ovary glabrous; style glabrous. Aggregate fruit purplish black at maturity, semiglobose, 8–10 mm in diam., glabrous; pyrenes slightly rugose. Fl. May–Jun, fr. Jul–Aug.

Sichuan, Yunnan.

Forests, bamboo forest margins, thickets, gravelly slopes; 1000--3100 m.

Rubus preptanthus là loài thực vật có hoa trong họ Hoa hồng. Loài này được Focke miêu tả khoa học đầu tiên năm 1910.

早花悬钩子（学名：Rubus preptanthus）为蔷薇科悬钩子属的植物，为中国的特有植物。分布于中国大陆的四川、云南等地，生长于海拔1,000米至2,700米的地区，见于生灌丛中及竹林边，目前尚未由人工引种栽培。